Fills your pores and makes your skin look smooth?

That’s just too good to be true, right?

I can still remember the first time I tried Smashbox Photo Finish. While I’m not a “full face of makeup” kind of gal, I do like a smooth finish and love any products that can help minimize the huge pores on my cheeks. And, if it’s possible to avoid looking like I dipped my forehead in olive oil during lunchtime, that’s a plus too.

Photo Finish did all that and more. My skin looked flawless even before I picked up the concealer, I didn’t need blotting papers before noon and my lightweight foundation stayed in place. All day. I was in love.

Fast forward a decade, and I still love the look of Photo Finish. But as a much more ingredient-conscious consumer, I realize its first two ingredients are cyclopentasiloxane and dimethicone – both silicones. Silicones have been getting a bad rap as of late, but are they really all that dangerous? Is it one of those ingredients that cause acne? Or can I continue enjoying my super-smooth pre-makeup skin?

First off, what is silicone?

Silicone is a synthetic polymer made up of silicon, oxygen and other elements, such as carbon and hydrogen. So while silicone is derived from natural ingredients, it has to go through significant chemical processes to become silicone (hence the synthetic part!). But just because it is synthetic doesn’t mean silicone is in the same category as parabens, phthalates and sulfates.

“Silicones are used in a variety of cosmetic products, from skincare to haircare,” explains cosmetic chemist Vanessa Thomas. “Common types of silicones include cyclopentasiloxane, cyclohexasiloxane, dimethicone and cetearyl methicone.”

Why are silicones used in beauty products?

The short answer? To give products a velvety feel and enable them to smooth imperfections and create a breathable barrier.

“Silicone’s main function is as an occlusive, which means it forms a barrier that resists water and air,” says Thomas. “Often, silicones are used in anti-frizz products, because they create a barrier around the hair, protecting the hair from moisture. Silicones also have the ability to aid in wound healing because of the barrier they create. They are able to shield wounds from infection, but at the same time, the barrier is breathable.”

Silicone’s occlusive and emollient properties help to fill in fine lines and make skin appear smoother, which is why it is often the star ingredient in makeup primers. You will also find silicone in BB creams, foundations and other cream-based cosmetics.

While the barrier silicone creates can lock in moisture on the skin’s surface, the ingredient doesn’t actually moisturize your skin. In fact, there aren’t any proven long-term benefits of using silicones. Silicones can make your skin look and feel healthier, plumper and smoother after you apply them, but as soon they wear or are washed off, you’re back to square one.

Does silicone clog pores? Or cause other skin issues?

“Because silicones create a film over the skin, this means that they can lock in dirt and oil,” says Thomas. “It is also difficult to wash off, so you will have to take extra steps in your cleansing routine to be sure you have rinsed the silicones off completely.”

Silicones are hypoallergenic, non-irritating and non-comedogenic. And most dermatologists agree that silicones are safe and shouldn’t cause an issue if you’re not typically prone to breakouts. However, if you have oily, sensitive or acne-prone skin, you may want to look for an alternative.

Even though they are safe for skin, many environmental activists are calling for consumers to avoid silicones, due to the fact that they are bioaccumulative. When washed off your face, silicones can accumulate and pose a risk to aquatic organisms.

The bottom line

Although silicones like dimethicone or cyclopentasiloxane aren’t dangerous or on the “ingredients to avoid” list, whether you want to use or avoid them really comes down to skin type or concerns (or personal preference). If you have acne-prone skin or simply don’t want to use silicones, there is certainly no shortage of great silicone-free primers, moisturizers and foundations to choose from.